Stress imposed on the wheels and suspension of heavy load bearing vehicles, occasioned by the irregularities of road surfaces, is a significant factor in tire performance and fuel efficiency. For fuel efficiency it is generally desirable to maintain a high pneumatic tire pressure. Particularly under load bearing conditions, the higher the pneumatic tire pressure the greater the shock imposed upon the wheels and suspension of the vehicle by irregular road surfaces such as holes and the like, and the greater the incidence of vehicle wheel and suspension breakdown. As a result, the selection of pneumatic tire pressure is generally lowered as a compromise to fuel and treadwear efficiency for reduced probability of suspension and wheel damage.
Attempts have been made to provide cushion wheel assemblies which enable the use of higher pneumatic tire pressures without the accompanying problems associated with shock. U.S. Pat. No. 1,895,579 discloses a cushion wheel assembly wherein a rigid circular rim is configured for mounting a pneumatic tire on the outer circumference thereof and an annular ring, comprising a series of elastomeric felloe-sections, is arranged between the inner circumference of the rigid circular rim and the outer circumference of a rigid hub comprising bearings and the like for mounting the wheel to an axle. Such arrangement relies upon vulcanized or the like bonding among the felloe-sections and other components of the arrangement to maintain the integrity of the assembly and such bonding is prone to failure during use.
British Provisional Patent 388,794 discloses a cushion wheel arrangement wherein a spoke wheel embodiment supporting a pneumatic tire, comprises a hub assembly having a resilient material surrounding a central component which has a complex arrangement for attachment to the hub. Such arrangement requires a complex procedure for removal of the wheel to enable changing a tire and has not enjoyed widespread commercial success.
An object of the present invention is to provide a suitable cushion assembly for a wheel which enables use of higher tire inflation pressures and yet reduces shock imposed upon a vehicle suspension system.
A further object of the invention is to provide a simple wheel cushion assembly which enables convenient and easy removal for tire and/or brake service.
These and other objects of the invention will become apparent from the following recitation of the invention.